High performance LiMnFePO4/Li4Ti5O12 full cells by functionalized polymeric additives

Abstract

Herein, we report a novel class of additives based on functional polymers for electrode fabrication. A small quantity of a 2,3-dimethoxybenzene (DMB)-based polymer was mixed with a state-of-the-art binder, poly(vinylene difluoride) (PVDF), to greatly improve the first fast charge–discharge and high-voltage LiMnFePO₄/Li₄Ti₅O₁₂ batteries operating at 3.0 V. Dual effects of the polymer were reported, i.e., trapping of soluble Mn²⁺ of positive electrodes and the in situ formation of a passivation layer on the negative electrode (AlF₃). Both effects are possible because a functional polymer was used; this synergic effect enhances the cell performance by 16.7% after more than 300 cycles at 45 °C and 1C.